I have a situation where my employer offered dental cover at a reasonable price and deducts £x from my wage to cover this each month

I recently submitted a claim on the policy and when I attempted to chase was advised that the premiums were not being paid and the claim would not be processed further.This has obviously left me out of pocket but my employer just continuously advises its "being dealt with"

So money is continued to be deducted for a policy they are not paying premiums for and is useless to me, whats more they have told me im locked into paying for 12 months (of which 8 remain)

As this is my employer I am not really sure what the legal position is and what I should be doing.